Word games?

This is my first attempt at a word game and I have absolutely no idea how to start.
Say for example I have two UIImageViews one with an image letter "A" and the other "B" and if I connected them to form "AB" how can I detect that and look it up in a list of words that I provide?
Or is that the wrong approach?
Anyone who has done a game that mixes and matches letters to make words know of a good place to start?

Well, say your grid was represented by an array of characters (NSString, char *, whatever). One method would be to go along each row, checking for a character. When one is found, add it to an array. Then check the next grid square, adding characters to the array until there's a blank cell or the end of the grid. Then use the array you've generated to make a string, and check if it exists in your dictionary.

What if my grid was represented by UIViews or UIImageViews?
I'm using UIViews/UIImageViews partly because it's the only way i know of how to actually represent a grid and use images.
I'm trying to figure out how to connect my "images" of each letter to actual letters and use those letters to determine words from a dictionary.